There was an article in Golf Weekly about rookie Gary Woodland. Essentially, Woodland was a former basketball player for Kansas and he's one of the longest hitters on tour, with a clubhead speed around 130 mph and a ball speed of 190 mph (most tour pros have an average clubhead speed of 115 and a ball speed of 170 mph). Woodland's swing coach, Randy Smith, said that Woodland has recorded a ball speed over 200 mph.
Anyway, here's a video of his swing. If you can manage to stop it right before impact, it's really impressive.